At the appointed time, her patients will dial in, and the 100-year-old psychologist will pick up the phone. Increasingly hard of hearing, she presses her cordless handset tightly to her ear. She is partly blind, and can no longer rely on reading her own notes. For 45 minutes, several times a week, she listens intently to the pains and conundrums of clients who have come to depend on her counsel.

Sometime after the Covid-19 pandemic, when all of her sessions went remote, the psychologist, Marcia Brenner, started to notice an upsetting tendency. She’d find herself asking for details about her patients’ lives that she once knew so intimately. This loss of memory may be the most painful affliction she has suffered in her very long life.

“It’s terribly frustrating, but there’s nothing I can do except to say, ‘Remind me, tell me again, repeat that,’” Dr. Brenner said. “I do the best I can not to display my distress.”

And yet she feels she would let her patients down if she retired.

“It goes back to an Eastern European hospitality thing,” her son Evan Brenner said, referring to the family’s heritage in the Minsk region of what is now Belarus. “You don’t say no to a guest or somebody asking for help.”

A home health aide who helps Dr. Brenner with scheduling and billing said that when the psychologist was in the hospital with a broken hip, patients called to ask when she would return.

And so she continues with her weekly therapy sessions. “It’s an effort,” Dr. Brenner said. “But I automatically get into a work mode. When I’m into a session, I can be my old self.”